Conventional bearing apparatuses include bearing surfaces that move relative to one another are known in the art. For example, radial bearings and so-called “thrust bearings” may conventionally include bearing surfaces that may at least partially contact and move or slide relative to one another or otherwise develop a fluid film between for hydrodynamic operation. Such bearing surfaces may include a superhard material for resisting wear during use of the bearing apparatus. In one example, bearing surfaces in a bearing apparatus may comprise a hard material such as diamond (e.g., polycrystalline diamond).
One application for bearing apparatuses, such as radial bearings and thrust bearings, is in association with drilling equipment utilized in subterranean drilling. Particularly, drilling motors have been utilized for drilling boreholes into subterranean formations, especially for oil or gas exploration. In a typical downhole drilling motor, the motor is suspended at the lower end of a string of drill pipe comprising a series of pipe sections connected together at joints and supported from the surface. A rotary drill bit (e.g., a fixed cutter drill bit, roller cone drill bit, a reamer, etc.) may be supported below the drilling motor (via pipe sections, drill collars, or other structural members as known in the art) or may be directly connected to the downhole motor, if desired. Drilling fluid is commonly circulated through the pipe string and the motor to generate torque within the motor, causing the rotary drill bit to rotate. The drilling fluid may then be returned to the surface through the annular space between the drilled borehole and the drill string and may carry the cuttings of the subterranean formation to the surface.
Downhole drilling motors may include bearing apparatuses, such as thrust bearings or radial bearings. In one embodiment, bearing assemblies comprised of a plurality of hard bearing elements, such as diamond bearing elements, may be coupled to the rotating bearing ring and the non-rotating bearing ring. The bearing elements are positioned adjacent one another so that the diamond bearing surfaces of the non-rotating bearing ring and rotating bearing ring may contact one another during certain operating conditions or may operate hydrodynamically under other operating conditions.
Bearing elements have traditionally been secured to bearing apparatuses through using various methods, including brazing the bearing elements to a rotating bearing ring and a non-rotating bearing ring of a bearing apparatus. However, conventional brazing techniques typically require exposing the parts to be brazed to high temperatures for extended periods of time to melt a brazing filler metal used to braze the parts. Bearing parts, such as rotating bearing rings and non-rotating bearing rings, are often placed in a heating oven for a few hours in order to heat the parts and the brazing filler metal to the appropriate brazing temperature.
During the manufacture of bearing assemblies, it can be difficult maintaining individual bearing elements in a desired position and orientation, relative to a bearing ring, while the bearing elements are affixed to the bearing ring. For example, the bearing elements may be brazed to the bearing ring, requiring the bearing assembly to be subjected to elevated temperatures. During such a high temperature process, the bearing elements may move or change their positions relative to the bearing ring, causing the bearing element to be out of an acceptable tolerance range and resulting in a bearing surface that does not match the geometric design of the bearing assembly.
It is a desire within the industry to continually improve bearing assemblies, bearing components, and the processes associated with manufacturing such components and assemblies.